Exhaust aftertreatment systems are used to receive and treat exhaust gas generated by IC engines. Generally exhaust gas aftertreatment systems include any of several different components to reduce the levels of harmful exhaust emissions present in the exhaust gas. For example, certain exhaust gas aftertreatment systems for diesel-powered IC engines include a selective catalytic reduction (SCR) system including a catalyst formulated to convert NOx (NO and NO2 in some fraction) into harmless nitrogen gas (N2) and water vapor (H2O) in the presence of ammonia (NH3). Generally in such aftertreatment systems, an exhaust reductant, (e.g., a diesel exhaust fluid such as urea) is injected into the SCR system to provide a source of ammonia, and mixed with the exhaust gas to partially reduce the NOx gases. The reduction byproducts of the exhaust gas are then fluidically communicated to the catalyst included in the SCR system to decompose substantially all of the NOx gases into relatively harmless byproducts which are expelled out of the aftertreatment system.
An exhaust reductant is generally inserted into the SCR system as the source of ammonia to facilitate the reduction of constituents such as NOx gases of the exhaust gas (e.g., a diesel exhaust gas) by the catalyst included in the SCR system. Reductant insertion assemblies which can include pumps, valves, fluid communication lines, orifices, nozzles, pressure relief valve, bypass valves and/or other fluid communication equipment are often used for controlled insertion of the reductant into the aftertreatment system, for example the SCR system of the aftertreatment system.
Some aftertreatment systems are fluidly coupled to large engines, for example high horse power (HHP) engines which generate a large amount of exhaust gas. Such aftertreatment systems often need a large amount of reductant to efficiently reduce the constituents of the exhaust gas produced by the large engines. To meet the high reductant demand, the reductant may be inserted at a plurality of locations in the aftertreatment system, for example via a plurality of injectors positioned at various locations on or upstream of an SCR system included in the aftertreatment system. Conventional reductant insertion assemblies used to provide the reductant to such aftertreatment systems generally include a plurality of pumps, each of which is dedicated for providing reductant to a particular location or otherwise, an injector of the SCR system. This increases the manufacturing and maintenance cost, as well as the power requirement and amount of space occupied by such reductant insertion assemblies.